VB.NET，对象是通过函数引用返回的 [英] VB.NET, Is Object Returned by Reference from Function
问题描述
这应该是一个相当普遍的问题，但是我在任何地方都找不到一个简单的答案.
This should be a fairly common question, but I haven't found a straightforward answer anywhere.
如果我在VB.NET中的函数中实例化一个对象并将其返回，则它是按引用还是按值返回它. IE浏览器-如果我写这样的话，我应该担心性能吗?
If I instantiate an object within a function in VB.NET and return it, does it return it by reference or by value. IE - should I be worried about performance if I write something like this:
Public Function ret_obj_func() As big_object
Dim ret_obj As New big_obj(<lots of stuff>)
Return ret_obj
End Function
如果我从其他地方调用此函数，它将在ret_obj中实例化该对象，然后创建一个深层副本以将副本传递回调用方，还是仅传递回引用?
If I call this function from somewhere else, will it instantiate the object in the ret_obj and then create a deep copy to pass back a copy to the caller, Or will it just pass back a reference?
推荐答案
它只是传回一个引用(假设big_obj是一个类).我在这里不使用通过引用"一词，因为在参数传递方面它具有微妙的含义-但假设big_obj是一个类-引用类型-ret_obj的值是一个引用，然后该引用将返回.
It just passes back a reference (assuming big_obj is a class). I wouldn't use the term "by reference" here, as that has a subtly different meaning when it comes to parameter passing - but assuming big_obj is a class - a reference type - the value of ret_obj is a reference, and that reference will be what's returned.
从VB的角度来看，我没有任何文章，但是如果您乐于看C#，您可能会发现这些文章很有用:
I don't have any articles on this from a VB perspective, but if you're happy to look at C#, you may find these articles useful:
- Reference and value types
- Parameter passing in C#
这篇关于VB.NET，对象是通过函数引用返回的的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
